Semi-rigid collapsible container

1 . A container for containing a heated liquid and having a longitudinal axis, the container comprising:

at least one substantially vertically folding vacuum panel portion disposed substantially transversely relative to the longitudinal axis, the vacuum panel portion adapted to compensate for vacuum pressure changes within the container caused by heating or cooling of a liquid contained within the container;

wherein the vacuum panel portion comprises an initiator portion and a control portion, with at least a portion of the control portion being more steeply inclined relative to the longitudinal axis than at least a portion of the initiator portion, and wherein the initiator portion causes the control portion to flex inwardly into the container;

further wherein the pressure panel inverts vertically in a direction substantially parallel to the longitudinal axis.

2 . The container of claim 1 , wherein the pressure panel portion inverts vertically under a longitudinally applied force substantially parallel with the longitudinal axis.

3 . The container of claim 2 , wherein the longitudinally applied force is an externally applied mechanical force.

4 . The container of claim 2 , wherein the longitudinally applied force is created by vacuum pressure developed within the container.

5 . The container of claim 1 , wherein the at least a portion of the control portion is linear when viewed in a vertical cross-section taken through the longitudinal axis.

6 . The container of claim 1 , wherein the at least a portion of the control portion is curved when viewed in a vertical cross-section taken through the longitudinal axis.

7 . The container of claim 6 , wherein a tangent line to the at least a portion of the control portion is more steeply inclined relative to the longitudinal axis than the at least a portion of the initiator portion.

8 . The container of claim 1 , wherein the at least a portion of the initiator portion is linear when viewed in a vertical cross-section taken through the longitudinal axis.

9 . The container of claim 1 , wherein the at least a portion of the initiator portion is curved when viewed in a vertical cross-section taken through the longitudinal axis.

10 . The container of claim 9 , wherein the at least a portion of the control portion is more steeply inclined relative to the longitudinal axis than is a tangent line to the at least a portion of the initiator portion.

11 . The container of claim 1 , wherein the initiator portion is located closer to the longitudinal axis than the control portion.

12 . The container of claim 1 , wherein the initiator portion is located farther from the longitudinal axis than the control portion.

13 . The container of claim 1 , wherein the initiator portion and the control portion are substantially continuous with one another.

14 . The container of claim 1 , wherein the initiator portion and the control portion are substantially discontinuous with one another.

15 . A container for containing a heated liquid and having a longitudinal axis, the container comprising:

at least one substantially vertically folding vacuum panel portion disposed substantially transversely relative to the longitudinal axis, the vacuum panel portion adapted to compensate for vacuum pressure changes within the container;

wherein the vacuum panel portion includes an initiator portion and a control portion, the control portion disposed nearer a side wall and further from the longitudinal axis than the initiator portion, the initiator portion providing for vertical folding before the control portion, wherein the vacuum panel portion inverts vertically under a longitudinally applied force substantially parallel with the longitudinal axis.

16 . The container of claim 15 , wherein the longitudinally applied force is an externally applied mechanical force.

17 . The container of claim 15 , wherein the longitudinally applied force is created by vacuum pressure developed within the container.

18 . The container of claim 15 , wherein the initiator portion and the control portion are substantially continuous with one another.

19 . The container of claim 15 , wherein the initiator portion and the control portion are substantially discontinuous with one another.

20 . A container for containing a heated liquid and having a longitudinal axis, the container comprising:

at least one substantially vertically folding vacuum panel portion disposed substantially transversely relative to the longitudinal axis, the vacuum panel portion adapted to compensate for vacuum pressure changes within the container caused by heating or cooling of a liquid contained within the container;

wherein the vacuum panel portion comprises an initiator portion and a control portion, with both the initiator portion and the control portion being curved when viewed in a vertical cross-section taken through the longitudinal axis;

wherein at least a portion of the control portion is more steeply inclined relative to the longitudinal axis than at least a portion of the initiator portion, and wherein the initiator portion causes the control portion to flex inwardly into the container;

further wherein the pressure panel inverts vertically in a direction substantially parallel to the longitudinal axis.

21 . The container of claim 20 , wherein the initiator portion and the control portion define a substantially continuous curve.

22 . The container of claim 20 , wherein the pressure panel portion inverts vertically under a longitudinally applied force substantially parallel with the longitudinal axis.

23 . The container of claim 22 , wherein the longitudinally applied force is an externally applied mechanical force.

24 . The container of claim 22 , wherein the longitudinally applied force is created by vacuum pressure developed within the container.